Meet WebP, Google's New Image Format

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Meet WebP, Google's New Image Format

As part of its self-imposed mission to make the web faster, Google has rolled its own image format.

It's called WebP, and it's based on open source technology. Google launched the initiative Thursday night with a post on its Chromium blog.

WebP has much in common with JPEG, the most widely used of the web's image formats. Like JPEG, the new format is intended to be used for photos on web pages, and like JPEG, the photos in a WebP image are compressed using lossy technology. The images will continue to reduce in quality the more you compress them.

But Google says WebP is more efficient than JPEG, and that it can shave away more than one third of the bulk in web images without any noticeable loss in quality. Google has been testing WebP's efficiency over the last few months, taking around a million images from the web (mostly JPEGs, but also some PNGs and GIFs) and running them through the new WebP compression technology.

It says its engineers have seen a 39 percent reduction in overall file size on these test images "without perceptibly compromising visual quality," and that it expects the results to improve once development picks up. Also, you could probably get even better results if you started from an uncompressed image.

WebP is being released as a developer preview, so its not supported by any major web browsers, camera manufacturers, or the software we use to make JPEGs, like Photoshop or iPhoto. Google will no doubt quickly build it into its own browser, Google Chrome, and its Picasa photo sharing software, but it will need some major backing from every key player in the browser and digital imaging hardware and software spaces if it's to gain any traction. So it doesn't present much of a challenge to JPEG right now.

It may in the future, though. Images are biggest data payload on web pages – when a page is slow to load, more often than not, it's the photos that are slowing it down. The industry as a whole has been trying to solve the page load speed issue for years, and focus has increased with the explosion of the mobile web and the growing frustration with the limits of cellular data networks.

Google has made several recent attempts to speed up web page load times, both with its own SPDY protocol for web applications and its work on WebKit and V8 engines for web browsers.

But because it's open source, and because it's been built on technologies proponents of the open web are already familiar with, WebP does have a chance. The first step is getting into Google Chrome, which the company says will happen very soon. After that, it's a matter of getting support from Mozilla, Opera, Apple and Microsoft to display WebP in its browsers. Considering how willing most of those companies were to play nice with WebM video, we should expect that to happen sooner rather than later.

In the meantime, Google is also considering some tricks to speed adoption, like writing scripts that pull JPEGs off the web and re-compress them in the WebP format, then store them for later use.